Xbase++ Requires Chilkat v11.5.0+

curl with Variable Substitution in a GraphQL Request Body

See more CURL Examples

This example shows how to use variables inside a graphql request body using the {{variable_name}} syntax. When the HTTP request’s Content-Type indicates graphql, Chilkat automatically applies proper escaping to each substituted value, ensuring the resulting graphql remains valid. Xbase++

LOCAL nSuccess
LOCAL oSbCurl
LOCAL oCurl
LOCAL oSbRawRequest

nSuccess := 0

nSuccess := 0

//  Variable names are enclosed between {{ and }}
//  Important: Variables should be placed inside the quotes.

//  curl -X POST https://api.example.com/graphql \
//    -H "Content-Type: application/graphql; charset=utf-8" \
//    -H "Accept: application/json" \
//    --data-binary "mutation {
//    createUser(
//      input: {
//        name: \"{{name}}\"
//        city: \"{{city}}\"
//        note: \"{{note}}\"
//        bio: \"{{bio}}\"
//      }
//    ) {
//      id
//      name
//    }
//  }"

//  Build the above curl command.
oSbCurl := CreateObject("Chilkat.StringBuilder")
oSbCurl:AppendLn("curl -X POST https://api.example.com/graphql \")
oSbCurl:AppendLn('  -H "Content-Type: application/graphql; charset=utf-8" \')
oSbCurl:AppendLn('  -H "Accept: application/json" \')
oSbCurl:AppendLn('  -d "mutation {')
oSbCurl:AppendLn("  createUser(")
oSbCurl:AppendLn("    input: {")
oSbCurl:AppendLn('      name: \"{{name}}\"')
oSbCurl:AppendLn('      city: \"{{city}}\"')
oSbCurl:AppendLn('      note: \"{{note}}\"')
oSbCurl:AppendLn('      bio: \"{{bio}}\"')
oSbCurl:AppendLn("    }")
oSbCurl:AppendLn("  ) {")
oSbCurl:AppendLn("    id")
oSbCurl:AppendLn("    name")
oSbCurl:AppendLn("  }")
oSbCurl:AppendLn('}"')

oCurl := CreateObject("Chilkat.HttpCurl")

//  Provide values for variables
oCurl:SetVar("name", "José O'Connor")
oCurl:SetVar("city", "München")
oCurl:SetVar("note", 'He said "Hello, world!" — and left…')
oCurl:SetVar("bio", "Loves sushi, café visits, and π ≈ 3.14159")

//  To demonstrate how the variables are replaced, this example does not execute the curl command. 
//  Instead, it generates the raw HTTP request that would be sent if the curl command were run.
oSbRawRequest := CreateObject("Chilkat.StringBuilder")
nSuccess := oCurl:ToRawRequest(oSbCurl:GetAsString(), oSbRawRequest)
IF (nSuccess == 0)
    ? oCurl:LastErrorText
    oSbCurl:destroy()
    oCurl:destroy()
    oSbRawRequest:destroy()
    RETURN
ENDIF

? oSbRawRequest:GetAsString()

//  The output is shown below.
//  Notice the quote chars around "Hello, world!" are properly escaped.

//  POST /graphql HTTP/1.1
//  Accept: application/json
//  Host: api.example.com
//  Content-Type: application/graphql; charset=utf-8
//  Content-Length: 250
//  
//  mutation {
//    createUser(
//      input: {
//        name: "José O'Connor"
//        city: "München"
//        note: "He said \"Hello, world!\" — and left…"
//        bio: "Loves sushi, café visits, and π ≈ 3.14159"
//      }
//    ) {
//      id
//      name
//    }
//  }

oSbCurl:destroy()
oCurl:destroy()
oSbRawRequest:destroy()